This study evaluates the impacts and costs of the Reading Partners program, which uses community volunteers to provide one-on-one tutoring to struggling readers in under-resourced elementary schools. The evaluation uses an experimental design. Students were randomly assigned within 19 different Reading Partners sites to a program or control condition to answer questions about the impact of the program on student reading proficiency. A cost study, using a subsample of six of the 19 study sites, explores the resources needed to implement the Reading Partners program as described in the evaluation. Findings indicate that the Reading Partners program has a positive and statistically significant impact on all three measures of reading proficiency assessed with an effect size equal to around 0.10. The cost study findings illustrate the potential value of the Reading Partners program from the schools' perspective because the financial and other resources required by the schools to implement the program are low. Additionally, the study serves as an example of how evaluations can rigorously examine both the impacts and costs of a program to provide evidence regarding effectiveness.